Laser processing method and apparatus

ABSTRACT

There is disclosed a laser processing method including moving a mask and a work with respect to each other while emitting a pulse laser a plurality of times, and moving the mask and the work with respect to each other to form respective laser irradiated regions disposed adjacent to one another by irradiating the work with the pulse laser transmitted through openings formed in positions different from one another on the mask, so that boundaries of the laser irradiated regions disposed adjacent to each other contact at least each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2001-032708, filed Feb.8, 2001, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a manufacturing process, forexample, of a polysilicon (p-Si) thin film transistor (TFT) liquidcrystal display, and to a laser processing method and apparatus in whicha workpiece such as an amorphous silicon (a-Si) film is irradiated witha pulse laser beam, and the a-Si film is poly-crystallized.

[0004] 2. Description of the Related Art

[0005] A manufacturing process of a p-Si TFT liquid crystal displayincludes a process of poly-crystallization. The process includes:forming an a-Si thin film on a glass substrate of the liquid crystaldisplay; and forming the thin film into a polycrystalline silicon (Si)film.

[0006] Examples of a method of poly-crystallization include a solidphase growth method and an excimer laser annealing method. The solidphase growth method includes annealing the a-Si film formed on the glasssubstrate at a high temperature so that a polycrystalline Si film isobtained. Since the solid phase growth method is a high-temperatureprocess, it is necessary to use an expensive quartz glass in the glasssubstrate.

[0007] The excimer laser annealing method includes irradiating the a-Sifilm with a short-pulse excimer laser having a pulse width of about 20ns so that the polycrystalline Si film is obtained. Since the excimerlaser annealing method is a low-temperature process, mass production canbe realized.

[0008] In the p-Si TFT liquid crystal display, an enhanced capabilityhas been requested to be realized. To realize the enhanced capability,there has been a stronger demand for further enlargement of a currentcrystal particle diameter of the polycrystalline Si film. Concretely,the crystal particle diameter is around 0.5 μm in the current method,and there has been a strong demand for setting of the diameter toseveral micrometers or more.

[0009] Reasons for this will be described. There is a numeric value ofmobility as a factor which influences the capability of a semiconductordevice. The mobility represents a movement speed of an electron. Themovement speed drops, when the crystal particle diameter is small andthere are many crystal particle fields in a path of the electron. Whenthe movement speed decreases, the enhanced capability of thesemiconductor device cannot be expected. Therefore, there is a demandfor enlargement of the crystal particle diameter of the polycrystallineSi film.

[0010] Examples of an enlargement method of the crystal particlediameter include techniques described, for example, in Jpn. Pat. Appln.KOKAI Publication No. 56-137546 and PCT National Publication No.2000-505241. The Jpn. Pat. Appln. KOKAI Publication No. 56-137546discloses a method for using a roof-shaped laser beam to scan a work.The PCT National Publication No. 2000-505241 discloses a method calledsuper lateral growth.

[0011] These methods include: successively irradiating an Si thin filmwith a laser beam having a linear or roof-shaped pattern insynchronization with movement of the Si thin film, that is, the glasssubstrate. The present inventors have verified that the crystal particlediameter of the polycrystalline Si film is enlarged by these methods.

[0012] However, in these methods, since the Si thin film is successivelyirradiated with the laser beam at an interval, the glass substrate hasto be moved for each irradiation with the laser beam. A movementdistance needs to be between about 0.1 μm and 1.0 μm.

[0013] Therefore, in order to form the Si thin film into thepolycrystalline Si film on a large-sized glass substrate, for example, a300 mm×400 mm glass substrate, the glass substrate has to be moved at aninterval of about 0.1 μm to 1.0 μm. To form the polycrystalline Si filmover the large-sized glass substrate, a throughput of several hours isrequired, and formation cannot be realized.

[0014] Examples of a method for forming the polycrystalline Si film at ahigher speed include a method described in Jpn. Pat. Appln. No.9-217213. This method includes: forming a plurality of repeated patterns1 on a mask as shown in FIG. 1; and moving the glass substrate by apitch of the pattern 1.

[0015] Subsequently, the glass substrate is irradiated with the laserbeam through the mask. In a region irradiated with the laser beam, acrystal grows, and the whole region irradiated with the laser beam ispoly-crystallized. FIG. 1 shows a crystal grown region 2.

[0016] Subsequently, the glass substrate is moved in a stepwise mannerby the region irradiated with the laser beam.

[0017] Subsequently, the glass substrate is irradiated with the laserbeam through the mask. In the region irradiated with the laser beam, thecrystal grows, and the whole region irradiated with the laser beam ispoly-crystallized.

[0018] Thereafter, the irradiation with the laser beam and the stepwisemovement of the glass substrate are repeated, and the whole glasssubstrate is poly-crystallized.

[0019] There is another method for forming the polycrystalline Si filmat a high speed. In the method, the pitch of the pattern 1 formed on themask is reduced as shown in FIG. 2, and the glass substrate is notmoved. This mask is used to grow the crystal in a region portionirradiated with the laser beam.

[0020] The method includes: using the mask with the repeated pattern,for example, having a pattern width of 2 μm and pitch of μm formedthereon to form, for example, a polycrystal having a length of 2 μm andwidth of 0.3 μm.

[0021] However, the former method requires a throughput of severalhours, is unrealistic, and has a low productivity. In this method, whena width of the laser beam is set, for example, to 5 μm or more as shownin FIG. 3, a heat gradient of a middle portion in the region irradiatedwith the laser beam is reduced.

[0022] Therefore, boundaries of opposite ends of the region irradiatedwith the laser beam have a large particle diameter, but the middleportion is micro-crystallized. Then, a transistor is formed on thecrystallized region, but the micro-crystallization forms an Si crystalfilm which inhibits enhancement of the capability of the transistor.

[0023] In the latter method, there are large influences of a stopoperation in a substrate conveyance system for moving the glasssubstrate in the stepwise manner, deceleration operation during restart,and an acceleration time. Therefore, the throughput in an actual massproduction line is not achieved, and a further high-speed processing isnecessary.

[0024] In the latter method for narrowing the pitch of the pattern 1,because of a heat influence from the adjacent pattern 1, a growth speedof a lateral direction (vertical to a film thickness direction) of theSi film is lowered. Therefore, in the latter method, a part of theregion irradiated with the laser beam, for example, the middle portionof the irradiated region is micro-crystallized, and a micro crystalregion 3 is formed as shown in FIG. 2.

[0025] Furthermore, when the pitch of the repeated pattern 1 isnarrowed, the whole surface of the region irradiated with the laser beamis micro-crystallized, and the mobility of the electron is lowered asshown in FIG. 4.

BRIEF SUMMARY OF THE INVENTION

[0026] An object of the present invention is to provide a laserprocessing method and apparatus in which a polycrystalline Si filmhaving a uniform and large particle diameter can be formed with a highthroughput.

[0027] According to a major aspect of the present invention, there isprovided a laser processing method for irradiating a mask with aplurality of openings formed therein with a pulse laser, and irradiatinga plurality of portions of a work to be processed with the pulse lasertransmitted through the plurality of openings at the same time. Themethod comprises: moving a mask and a work with respect to each otherwhile emitting the pulse laser a plurality of times; and setting arelation between a relative movement speed of the mask and the work andan emission timing of the pulse laser such that respective laserirradiated regions disposed adjacent to one another on the work areformed by irradiation with the pulse laser transmitted through theopenings formed in positions different from one another on the mask, andboundaries of the respective laser irradiated regions disposed adjacentto each other contact at least each other.

[0028] According to another major aspect of the present invention, thereis provided a laser processing apparatus for irradiating a mask with aplurality of openings formed therein with a pulse laser, and irradiatinga plurality of portions of a work to be processed with the pulse lasertransmitted through the plurality of openings at the same time. Theapparatus comprises: a laser device for outputting the pulse laser; amoving section which moves the mask and the work with respect to eachanother; and a controller which controls the moving section to move themask and the work with respect to each other, and controls the laserdevice to emit the pulse laser a plurality of times. The controllercontrols the moving section to move the mask and the work with respectto each other so that respective laser irradiated regions disposedadjacent to one another are irradiated with the pulse laser transmittedthrough the openings different from one another among the plurality ofopenings, and boundaries of the respective laser irradiated regionsdisposed adjacent to each other contact at least each other.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0029]FIG. 1 is a schematic view showing a conventional method forforming a polycrystalline Si film;

[0030]FIG. 2 is a schematic view showing a conventional method fornarrowing a pitch of a repeated pattern and forming the polycrystallineSi film;

[0031]FIG. 3 is a schematic view showing a relation between aconventional laser beam width and micro crystal generation;

[0032]FIG. 4 is a schematic view showing a conventional method fornarrowing the pitch of the repeated pattern and forming thepolycrystalline Si film;

[0033]FIG. 5 is a constitution diagram showing a laser processingapparatus according to a first embodiment of the present invention;

[0034]FIG. 6 is a constitution diagram of a mask in the laser processingapparatus according to the first embodiment of the present invention;

[0035]FIG. 7 is a diagram showing a region crystallized by a first shotof pulse laser beam;

[0036]FIG. 8 is a diagram showing a region crystallized by a second shotof pulse laser beam;

[0037]FIG. 9 is a diagram showing a region crystallized by a third shotof pulse laser beam;

[0038]FIG. 10 is a diagram showing a region crystallized by a fourthshot of pulse laser beam;

[0039]FIG. 11 is a diagram showing a region crystallized by a fifth shotof pulse laser beam;

[0040]FIG. 12 is a constitution diagram of the mask in the laserprocessing apparatus according to a second embodiment of the presentinvention;

[0041]FIG. 13 is a diagram showing the region crystallized by the firstshot of pulse laser beam;

[0042]FIG. 14 is a diagram showing the region crystallized by the secondshot of pulse laser beam;

[0043]FIG. 15 is a diagram showing the region crystallized by the thirdshot of pulse laser beam;

[0044]FIG. 16 is a diagram showing the region crystallized by the fourthshot of pulse laser beam;

[0045]FIG. 17 is a diagram showing the region crystallized by the fifthshot of pulse laser beam;

[0046]FIG. 18 is a constitution diagram of the mask in the laserprocessing apparatus according to a third embodiment of the presentinvention;

[0047]FIG. 19 is a diagram showing the region crystallized by the firstshot of pulse laser beam;

[0048]FIG. 20 is a diagram showing the region crystallized by the secondshot of pulse laser beam;

[0049]FIG. 21 is a diagram showing the region crystallized by the thirdshot of pulse laser beam;

[0050]FIG. 22 is a constitution diagram of the mask in the laserprocessing apparatus according to a fourth embodiment of the presentinvention;

[0051]FIG. 23 is a diagram showing the region crystallized by the firstshot of pulse laser beam;

[0052]FIG. 24 is a diagram showing the region crystallized by the secondshot of pulse laser beam;

[0053]FIG. 25 is a diagram showing the region crystallized by the thirdshot of pulse laser beam;

[0054]FIG. 26 is a constitution diagram of the mask in the laserprocessing apparatus according to a fifth embodiment of the presentinvention;

[0055]FIG. 27 is a diagram showing a growth direction of a polycrystalwhen the mask in the fifth embodiment is used;

[0056]FIG. 28 is a constitution diagram of the mask in the laserprocessing apparatus according to a sixth embodiment of the presentinvention;

[0057]FIG. 29 is a diagram showing the growth direction of thepolycrystal when the mask in the sixth embodiment is used;

[0058]FIG. 30 is a constitution diagram of the mask in the laserprocessing apparatus according to a seventh embodiment of the presentinvention;

[0059]FIG. 31 is a diagram showing the region crystallized by the firstshot of pulse laser beam;

[0060]FIG. 32 is a diagram showing the region crystallized by the secondshot of pulse laser beam;

[0061]FIG. 33 is a diagram showing the region crystallized by the thirdshot of pulse laser beam;

[0062]FIG. 34 is a diagram showing an overlap of the regions irradiatedwith the respective shots of laser;

[0063]FIG. 35 is an explanatory view of a manufacturing method of a TFTliquid crystal display to which the laser processing apparatus of theseventh embodiment of the present invention is applied;

[0064]FIG. 36 is an explanatory view of the manufacturing method ofanother TFT liquid crystal display to which the laser processingapparatus of an eighth embodiment of the present invention is applied;

[0065]FIG. 37 is a constitution diagram of an exposure device accordingto a ninth embodiment of the present invention;

[0066]FIG. 38 is a schematic view showing a first exposure processing inthe exposure device;

[0067]FIG. 39 is a schematic view showing a second exposure processingin the exposure device;

[0068]FIG. 40 is a schematic view showing a transfer result in theexposure device; and

[0069]FIG. 41 is a schematic view showing a transfer action by aconventional exposure device.

DETAILED DESCRIPTION OF THE INVENTION

[0070] A first embodiment of the present invention will be describedhereinafter with reference to the drawings.

[0071]FIG. 5 is a constitution diagram of a laser processing apparatus.The laser processing apparatus is applied to manufacturing of a p-Si TFTliquid crystal display which has a process of poly-crystallization of ana-Si film formed on a glass substrate 10.

[0072] An excimer laser 11 outputs a pulse laser, for example, at arepeated frequency of 200 to 500 Hz. The excimer laser 11 outputs thepulse laser whose energy density of an irradiated point on the a-Si filmis of the order of 200 to 500 J/cm². The point irradiated with the pulselaser forms a processed point on the a-Si film.

[0073] A variable attenuator 12, lighting optical system 13, mask 14,and mirror 15 are disposed along an optical path of the pulse laser. Aprojection lens 16 is disposed on a reflected light path of the mirror15.

[0074] The lighting optical system 13 is constituted of a homogenizer,and a beam shaping optical system of the pulse laser beam. Concretely,the lighting optical system 13 includes a collimator lens 17, array lensgroup 18, and field lens 19.

[0075] The homogenizer forms the pulse laser beam as a beam having auniform strength on the mask 14. The homogenizer is formed by acombination of the field lens 19 and array lens group 18.

[0076] The projection lens 16 transfers a mask pattern formed on themask 14 onto the a-Si film.

[0077] Eight line patterns 20 as openings are formed in the samedirection in the mask 14. A width and pitch of the line pattern 20 isformed in sizes to form a polycrystalline Si film having a predeterminedor larger crystal particle diameter, when the a-Si film is irradiatedwith the pulse laser and poly-crystallized.

[0078] The width of each line pattern 20 is formed in such a line widthlength that a heat gradient is generated in the laser irradiated regionobtained by irradiating the a-Si film with the pulse laser. The pitchbetween the line patterns 20 is formed in a pitch interval such that theheat gradient is generated in the laser irradiated region obtained, whenirradiating the a-Si film with the pulse laser.

[0079] A constitution of the mask 14 will concretely be described withreference to FIG. 6.

[0080] The mask 14 is divided into a plurality of regions, for example,first to fourth mask regions M₁ to M₄. An interval among these maskregions M₁ to M₄ is formed in an interval having an equal pitch Mp.

[0081] The respective line patterns 20 are formed in positions which donot overlap one another in the respective mask regions M₁ to M₄.

[0082] For description of the position of each line pattern 20,respective origins Z₁ to Z₄ are disposed with respect to the maskregions M₁ to M₄. The respective line patterns 20 are formed inpositions having different distances from the origins Z₁ to Z₄ in themask regions M₁ to M₄.

[0083] For example, two line patterns 20 are separate from each other bya predetermined pitch in the mask region M₁, and the line pattern 20 onthe right side in the drawing is formed in a position aligned with theorigin Z₁.

[0084] In the mask region M₂, two line patterns 20 are separate fromeach other by the same pitch as the pitch of the line patterns 20 of themask region M₁, and are formed on the left side of the origin Z₂, forexample, by a line pattern width.

[0085] In the mask region M₃, two line patterns 20 are separate fromeach other by the same pitch as the pitch of the line patterns 20 of themask region M₁, and are formed on the left side from the origin Z₃, forexample, by a length twice that of the line pattern width.

[0086] In the mask region M₄, two line patterns 20 are separate fromeach other by the same pitch as the pitch of the line patterns 20 of themask region M₁, and are formed on the left side from the origin Z₄, forexample, by a length three times that of the line pattern width. In themask region M₄, the shown left line pattern 20 is formed on the leftmostside of the mask region M₄.

[0087] Each line pattern 20 is formed so that the laser irradiatedregion on the a-Si film has, for example, a beam width of about 5 μm orless and a pitch of 1 μm or more.

[0088] For a condition for forming the polycrystalline Si film having apredetermined or larger crystal particle diameter, the laser irradiatedregion on the a-Si film has each beam width of about 5 μm or less and apitch Mp of 1 μm or more.

[0089] The condition that the beam width is 5 μm or less influences athickness of the a-Si film formed on the glass substrate 10. When thea-Si film is irradiated, for example, with a single line beam, thecrystal grows toward a middle portion from an outer edge of the linebeam, and the whole surface of the laser irradiated region ispoly-crystallized on this condition.

[0090] The condition that the pitch Mp of the beam width is 1 μm or moreis influenced by the width of the line beam and the thickness of thea-Si film, and changes. This condition undergoes a heat influence fromthe adjacent line pattern, unless the interval of the respective linebeams is 1 μm or more based on at least a general resolution and heatdiffusion distance of the optical system.

[0091] The glass substrate 10 is laid on an XYZ tilt stage 21. The XYZtilt stage 21 moves the glass substrate 10 in X, Y, and Z directions.The X, Y, and Z directions cross at right angles to one another. The XYZtilt stage 21 raster-scans the pulse laser on the glass substrate 10 bythe movement of the XYZ directions.

[0092] Concretely, the XYZ tilt stage 21 moves, for example, the glasssubstrate 10 continuously in the X direction at a conveyance speedsynchronized with the repeated frequency of the pulse laser. In thiscase, the conveyance direction is a positive or negative X direction.

[0093] Moreover, the XYZ tilt stage 21 moves the glass substrate 10 inthe Y direction by a distance corresponding to the width of the pulselaser beam.

[0094] Subsequently, the XYZ tilt stage 21 again moves the glasssubstrate 10 continuously in the X direction at the conveyance speedsynchronized with the repeated frequency of the pulse laser. In thiscase, the X direction of the conveyance is reverse to the previous Xdirection, that is, the negative or positive X direction.

[0095] Thereafter, the XYZ tilt stage 21 repeats the aforementionedmovement.

[0096] The XYZ tilt stage 21 moves the glass substrate 10, for example,at a conveyance speed of about 200 to 500 mm/s.

[0097] A controller 22 controls the XYZ tilt stage 21 to move the glasssubstrate 10 at a constant speed so that the pulse laser raster-scansthe glass substrate 10. Moreover, the controller 22 controls the excimerlaser 11 to emit the pulse laser at a constant timing a plurality oftimes.

[0098] The controller 22 irradiates the respective laser irradiatedregions disposed adjacent to one another on the a-Si film with the pulselaser transmitted through the different line patterns 20. Moreover, thecontroller 22 moves the glass substrate 10 so that the respectiveboundaries of the laser irradiated regions adjacent to one anothercontact one another.

[0099] A focus displacement meter 23 measures displacement with the a-Sifilm on the glass substrate 10, and feeds a displacement signal back tothe XYZ tilt stage 21. The XYZ tilt stage 21 vertically moves the glasssubstrate 10 in the Z direction based on the fed-back displacementsignal. Thereby, an image of a mask pattern is formed on the a-Si filmon the glass substrate 10.

[0100] An operation of the apparatus constituted as described above willnext be described.

[0101] A manufacturing process of a p-Si TFT liquid crystal displayincludes a photolithography process. The photolithography processincludes a process of forming an a-Si thin film on the glass substrate10, a process of coating the thin film with a resist, a process ofperforming an exposure processing, a developing process, a process of anetching processing, and a process of removing the resist.

[0102] The photolithography process includes a process ofpoly-crystallizing the a-Si film on the glass substrate 10.

[0103] The method of poly-crystallizing the a-Si film on the glasssubstrate 10 is carried out as follows.

[0104] The excimer laser 11 intermittently outputs the pulse laser, forexample, at a repeated frequency of 200 to 500 Hz. The pulse laser isemitted to the mask 14 from the variable attenuator 12 through thelighting optical system 13.

[0105] The pulse laser is passed through the mask pattern formed on themask 14, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0106] Moreover, the XYZ tilt stage 21 moves the glass substrate 10 inthe X direction at the conveyance speed synchronized with the repeatedfrequency of the pulse laser beam. In this case, the conveyancedirection is the positive or negative X direction.

[0107] Subsequently, the XYZ tilt stage 21 moves the glass substrate 10in the Y direction by a distance corresponding to the width of the pulselaser beam.

[0108] Next, the XYZ tilt stage 21 again moves the glass substrate 10continuously in the X direction. In this case, the conveyance directionis the negative or positive X direction.

[0109] Thereafter, the XYZ tilt stage 21 repeats the aforementionedmovement.

[0110] The XYZ tilt stage 21 moves the glass substrate 10, for example,at the conveyance speed of about 200 to 500 mm/s.

[0111] The a-Si film on the glass substrate 10 is irradiated with first,second, third, . . . shots of pulse laser beams output from the excimerlaser 11 through the mask 14.

[0112]FIG. 7 shows each laser irradiated region Q₁ poly-crystallizedwhen the a-Si film is irradiated with the first shot of pulse laserbeam. The pulse laser beam passed through each line pattern 20 of themask 14 is emitted onto the a-Si film on the glass substrate 10. Thea-Si film of the laser irradiated region Q₁ is poly-crystallized bythese pulse laser beams.

[0113] Each laser irradiated region Q₁ is set such that each beam widthis 5 μm or less and the pitch Mp is 1 μm or more. Thereby, in each laserirradiated region Q₁, the crystal grows toward the middle portion fromthe outer edge of the laser irradiated region, and the whole surface ofthe laser irradiated region Q₁ is poly-crystallized to form thepolycrystalline Si film having the predetermined or larger crystalparticle diameter.

[0114] Each laser irradiated region Q₁ does not undergo any heatinfluence from the adjacent laser irradiated region, and the a-Si filmis poly-crystallized.

[0115] Subsequently, FIG. 8 shows a laser irradiated region Q₂poly-crystallized when the a-Si film is irradiated with the second shotof pulse laser beam.

[0116] Here, a region W₁ irradiated with the first shot of pulse laserwill be noted in the following description.

[0117] At the second shot, the first mask region M₁ moves toward theleft side in the drawing from the position irradiated with the firstshot of pulse laser.

[0118] Therefore, the region Q₂ irradiated with the second shot of laseris adjacent to the laser irradiated region Q₁ poly-crystallized by thepulse laser beam passed through each line pattern 20 of the second maskregion M₂ at the first shot.

[0119] Here, the laser irradiated regions Q₁ and Q₂ are formed by thepulse laser passed through the different line patterns 20, not by thepulse laser passed through the same line pattern 20.

[0120] Therefore, in the region W₁, the laser irradiated region Q₂ atthe second shot does not undergo any heat influence from the adjacentlaser irradiated region. The laser irradiated region Q₂ is obtained bypoly-crystallizing the a-Si film in the predetermined or larger crystalparticle diameter.

[0121] Next, FIG. 9 shows a laser irradiated region Q₃ poly-crystallizedwhen the a-Si film is irradiated with the third shot of pulse laser.

[0122] In the region W₁, the first mask region M₁ further moves towardthe left side in the drawing from the position irradiated with thesecond shot of pulse laser.

[0123] Therefore, the laser irradiated region Q₃ at the third shot isadjacent to the region Q₂ poly-crystallized by the pulse laser beampassed through each line pattern 20 of the second mask region M₂ at thesecond shot.

[0124] The laser irradiated region Q₃ at the third shot does not undergoany heat influence from the adjacent laser irradiated region, and thea-Si film is poly-crystallized in the predetermined or larger crystalparticle diameter.

[0125] Thereafter, similarly as described above, the pulse laser isemitted onto the a-Si film on the glass substrate 10 through the mask14, and the glass substrate 10 is continuously moved by the operation ofthe XYZ tilt stage 21.

[0126]FIG. 10 shows a laser irradiated region Q₄ poly-crystallized by afourth shot of pulse laser beam. FIG. 11 shows a laser irradiated regionQ₅ poly-crystallized by a fifth shot of pulse laser beam.

[0127] These regions Q₄, Q₅ do not undergo any heat influence from theadjacent laser irradiated region, and the a-Si film is poly-crystallizedin the predetermined or larger crystal particle diameter.

[0128] Therefore, for the a-Si film on the glass substrate 10, a nonlaser irradiated region not irradiated with the pulse laser issuccessively filled up, and finally the whole surface of the a-Si filmon the glass substrate 10 is poly-crystallized.

[0129] As described, in the first embodiment, the mask 14 is used inwhich the width of the line pattern 20 has a slit width to generate theheat gradient in the laser irradiated region obtained when irradiatingthe a-Si film with the pulse laser, and the pitch is formed in a pitchinterval to generate the heat gradient in the laser irradiated region.The pulse laser is emitted onto the glass substrate 10 at a timingcorresponding to the conveyance speed of the glass substrate 10. Thea-Si film on the glass substrate 10 is irradiated with the pulse laserthrough the mask 14, and the glass substrate 10 is continuously moved bythe operation of the XYZ tilt stage 21.

[0130] Thereby, while the glass substrate 10 is continuously moved, thea-Si film on the glass substrate 10 can continuously be formed into thepolycrystalline Si film having the uniform and predetermined or largercrystal particle diameter.

[0131] Therefore, the polycrystalline Si film can be formed at the highspeed. Mobility of an electron can be enhanced by forming thepolycrystalline Si film having the large crystal particle diameter. Forexample, a capability of a transistor formed on the Si crystallized filmis enhanced, and the capability of the p-Si TFT liquid crystal displaycan be enhanced.

[0132] In the manufacturing process of the p-Si TFT liquid crystaldisplay, productivity in poly-crystallizing the a-Si film on the glasssubstrate 10 can be enhanced. Thereby, a high throughput can beobtained.

[0133] To poly-crystallize the a-Si film on the whole surface of theglass substrate 10, when the XYZ tilt stage 21 continuously moves theglass substrate 10 in the X direction, subsequently moves the glasssubstrate 10 in the Y direction, and again moves the substratecontinuously in the X direction, an action of poly-crystallization istemporarily stopped. This is a natural operation from the shape of theglass substrate 10.

[0134] A second embodiment of the present invention will next bedescribed with reference to the drawings.

[0135] In the laser processing apparatus of the second embodiment, themask 14 shown in FIG. 5 is modified. Therefore, the laser processingapparatus will be described using the laser processing apparatus shownin FIG. 5.

[0136]FIG. 12 is a constitution diagram of a mask 30 for use in thelaser processing apparatus.

[0137] In the mask 30, square patterns 31 as openings are formed in thesame direction. The width and pitch of the square pattern 31 are formedin the sizes to form the polycrystalline Si film having thepredetermined or larger crystal particle diameter, when the a-Si film isirradiated with the pulse laser and poly-crystallized.

[0138] The width of each square pattern 31 is formed in a slit widthlength to generate the heat gradient in the laser irradiated region,when the a-Si film is irradiated with the pulse laser. The pitch betweenthe square patterns 31 is formed in the pitch interval to generate theheat gradient in the laser irradiated region, when the a-Si film isirradiated with the pulse laser.

[0139] A constitution of the mask 30 will concretely be described.

[0140] The mask 30 is divided into a plurality of divided regions, forexample, first to fourth mask regions M₁₁ to M₁₄. Each interval amongthese mask regions M₁₁ to M₁₄ is formed in the interval having the equalpitch Mp.

[0141] The respective square patterns 31 are formed in positions whichdo not overlap one another in the respective mask regions M₁₁ to M₁₄.

[0142] For the description of the position of each square pattern 31,respective origins Z₁₁ to Z₁₄ are disposed with respect to the maskregions M₁₁ to M₁₄. The respective square patterns 31 are formed inpositions having different distances from the origins Z₁₁ to Z₁₄ in themask regions M₁₁ to M₁₄.

[0143] For example, in the mask region M₁₁, the plurality of squarepatterns 31 are arranged in two rows in the Y direction. These squarepatterns 31 are separated from one another at a predetermined pitch inthe X and Y directions, and the square pattern 31 on the right side inthe drawing is aligned with the origin Z₁₁.

[0144] In the mask region M₁₂, the plurality of square patterns 31 arearranged in two rows in the Y direction. These square patterns 31 areseparated from one another at the predetermined pitch in the X and Ydirections, and the square pattern 31 on the right side in the drawingis formed in a position apart from the origin Z₁₂ by a predeterminedpitch in the Y direction.

[0145] In the mask region M₁₃, the plurality of square patterns 31 arearranged in two rows in the Y direction. These square patterns 31 areseparated from one another at the predetermined pitch in the X and Ydirections, and the square pattern 31 on the right side in the drawingis formed in a position apart from the origin Z₁₃ by the predeterminedpitch in the X and Y directions.

[0146] In the mask region M₁₄, the plurality of square patterns 31 arearranged in two rows in the Y direction. These square patterns 31 areseparated from one another at the predetermined pitch in the X and Ydirections, and the square pattern 31 on the right side in the drawingis formed in a position apart from the origin Z₁₄ by the predeterminedpitch in the X direction.

[0147] The width and pitch of the square pattern 31 have values suchthat the heat gradient is generated in the laser irradiated region inthe a-Si film formed on the glass substrate 10. For example, the beamwidth of the laser irradiated region on the a-Si film is set to about 5μm or less, and the pitch is set to about 5 μm or more.

[0148] An operation of the apparatus constituted as described above willnext be described.

[0149] The excimer laser 11 intermittently outputs the pulse laser, forexample, at a repeated frequency of 200 to 500 Hz. The pulse laser isemitted to the mask 30 from the variable attenuator 12 through thelighting optical system 13.

[0150] The pulse laser is passed through the mask pattern formed on themask 30, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0151] Moreover, similarly as the first embodiment, the XYZ tilt stage21 continuously moves the glass substrate 10 at the conveyance speedsynchronized with the repeated frequency of the pulse laser beam.

[0152] The first, second, third, shots of pulse laser beams output fromthe excimer laser 11 are emitted onto the a-Si film on the glasssubstrate 10 through the mask 30.

[0153]FIG. 13 shows each square laser irradiated region Apoly-crystallized when the a-Si film is irradiated with the first shotof pulse laser beam. The a-Si film on the glass substrate 10 isirradiated with the pulse laser beams passed through the respectivesquare patterns 31 of the mask 30. The a-Si film of the laser irradiatedregion A with these pulse laser beams is poly-crystallized.

[0154] In each laser irradiated region A, the beam width is set to 5 μmor less, and the pitch Mp is set to 5 μm or more. Thereby, in the laserirradiated region A, the crystal grows toward the middle portion fromthe outer edge, and the whole surface of the laser irradiated region Ais poly-crystallized to form the polycrystalline Si film having thepredetermined or larger crystal particle diameter.

[0155] In each laser irradiated region A, the a-Si film ispoly-crystallized without undergoing any heat influence from theadjacent laser irradiated region.

[0156] Here, a region W₂ irradiated with the first shot of pulse laserwill be noted in the following description.

[0157]FIG. 14 shows a laser irradiated region B poly-crystallized whenthe a-Si film is irradiated by the second shot of pulse laser. At thesecond shot, the laser irradiated region B is poly-crystallized by thepulse laser passed through each square pattern 31 of the second maskregion M₁₂. The laser irradiated region B is adjacent to a lower edge ofthe region A poly-crystallized at the first shot.

[0158] The laser irradiated region B at the second shot does not undergoany heat influence from the adjacent laser irradiated region. In thelaser irradiated region B, the a-Si film is poly-crystallized to havethe predetermined or larger crystal particle diameter.

[0159] Next, FIG. 15 shows a laser irradiated region C poly-crystallizedwhen the a-Si film is irradiated with the third shot of pulse laser. Atthe third shot, the laser irradiated region C is poly-crystallized bythe pulse laser passed through each square pattern 31 of the third maskregion M₁₃. The laser irradiated region C is adjacent to a left edge ofthe laser irradiated region B poly-crystallized at the second shot.

[0160] The laser irradiated region C at the third shot does not undergoany heat influence from the adjacent laser irradiated region. In thelaser irradiated region C, the a-Si film is poly-crystallized to havethe predetermined or larger crystal particle diameter.

[0161] Next, FIG. 16 shows a laser irradiated region D poly-crystallizedwhen the a-Si film is irradiated by the fourth shot of pulse laser. Atthe fourth shot, the laser irradiated region D is poly-crystallized bythe pulse laser passed through each square pattern 31 of the fourth maskregion M₁₄. The laser irradiated region D is adjacent to an upper edgeof the laser irradiated region C poly-crystallized at the third shot.

[0162] The laser irradiated region D at the fourth shot does not undergoany heat influence from the adjacent laser irradiated region. In thelaser irradiated region D, the a-Si film is poly-crystallized to havethe predetermined or larger crystal particle diameter.

[0163] Subsequently, the a-Si film is irradiated with the fifth shot ofpulse laser. As shown in FIG. 17, a laser Irradiated region E ispoly-crystallized to have the predetermined or larger crystal particlediameter without undergoing any heat influence from the adjacent laserirradiated region.

[0164] Therefore, for the a-Si film on the glass substrate 10, the nonlaser irradiated region not irradiated with the pulse laser issuccessively filled up, and finally the whole surface of the a-Si filmon the glass substrate 10 is poly-crystallized.

[0165] As described, in the second embodiment, the mask 30 is used inwhich the width of the square pattern 31 has the slit width length togenerate the heat gradient in the laser irradiated region obtained whenirradiating the a-Si film with the pulse laser, and the pitch is formedin the pitch interval to generate the heat gradient in the laserirradiated region obtained when irradiating the a-Si film with the pulselaser. Thereby, the second embodiment produces an effect similar to theeffect of the first embodiment.

[0166] When the mask 30 is used, a micro crystal region is inevitablygenerated by irradiation with the fourth shot of pulse laser, and thesize of the square pattern 31 remains at 5 μm or less, the pitch may beset to be twice as large as the size of the square pattern.

[0167] In this case, in order to fill up at least the non-irradiatedregion with the pulse laser, at least six or more shots of pulse laserbeams are necessary, and the region on the mask 30 is divided into six.

[0168] A third embodiment of the present invention will next bedescribed with reference to the drawings.

[0169] In the laser processing apparatus of the third embodiment, theconstitution of the mask 14 shown in FIG. 5 is changed. Therefore, thelaser processing apparatus will be described using the laser processingapparatus shown in FIG. 5.

[0170]FIG. 18 is a constitution diagram of a mask 40 for use in thelaser processing apparatus.

[0171] In the mask 40, a plurality of dotted openings (hereinafterreferred to as a dotted pattern) 41, and a plurality of ring-shapedopenings (hereinafter referred to as square ring patterns) 42-1, 42-2are formed.

[0172] The dotted pattern 41 and square ring patterns 42-1, 42-2 areformed in positions which do not overlap one another in first to thirdmask regions M₂₁ to M₂₃.

[0173] These dotted pattern 41 and square ring patterns 42-1, 42-2 areformed in the respective widths and pitches such that the heat gradientappears at a time of irradiation of the glass substrate 10 with thepulse laser.

[0174] The constitution of the mask 40 will concretely be described.

[0175] The mask 40 is divided, for example, into first to third maskregions M₂₁ to M₂₃. Respective origins Z₂₁ to Z₂₃ are set in the maskregions M₂₁ to M₂₃.

[0176] In the first mask region M₂₁, the plurality of dotted patterns 41are formed at the equal pitch in two rows in the Y direction. The dottedpattern 41 is set at such a value that the heat gradient is generated inthe laser irradiated region in the a-Si film, for example, such that thebeam width of the laser irradiated region on the a-Si film is about 5 μmor less.

[0177] In the second mask region M₂₂, the plurality of square ringpatters 42-1 are formed at the equal pitch in two rows in the Ydirection. For the square ring pattern 42-1, the size of a square formedinside a ring agrees with the size of the dotted pattern 41. The squarering pattern 42-1 is set at such a value that the heat gradient isgenerated in the laser irradiated region in the a-Si film, for example,such that the beam width of the laser irradiated region on the a-Si filmis about 5 μm or less.

[0178] In the third mask region M₂₃, the plurality of square ringpatterns 42-2 are formed at the equal pitch in two rows in the Ydirection. For the square ring pattern 42-2, the size of the squareformed inside the ring agrees with an outer size of the square ringpattern 42-2. The square ring pattern 42-2 is set at such a value thatthe heat gradient is generated in the laser irradiated region in thea-Si film, for example, such that the beam width of the laser irradiatedregion on the a-Si film is about 5 μm or less.

[0179] A distance between a center of the dotted pattern 41 and theorigin Z₂₁, the distance between the center of the square ring pattern42-1 and the origin Z₂₂, and the distance between the center of thesquare ring pattern 42-2 and the origin Z₂₃ are substantially the same.

[0180] Therefore, when the first to third mask regions M₂₁ to M₂₃ aresuperposed upon one another, the dotted pattern 41 is disposed in thecenter, the square ring pattern 42-1 is disposed in the outer peripheryof the dotted pattern 41, and the square ring pattern 42-2 is disposedin the outer periphery of the square ring pattern 42-1.

[0181] The operation of the apparatus constituted as described abovewill next be described.

[0182] The method of poly-crystallizing the a-Si film formed on theglass substrate 10 in the manufacturing process of the p-Si TFT liquidcrystal display is carried out as follows.

[0183] The excimer laser 11 intermittently outputs the pulse laser beam,for example, at the repeated frequency of 200 to 500 Hz. The pulse laseris emitted to the mask 40 from the variable attenuator 12 through thelighting optical system 13.

[0184] The pulse laser is passed through the mask pattern formed on themask 40, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0185] Moreover, similarly as the first embodiment, the XYZ tilt stage21 continuously moves the glass substrate 10 at the conveyance speedsynchronized with the repeated frequency of the pulse laser beam.

[0186] The first, second, third, . . . shots of pulse laser output fromthe excimer laser 11 are emitted onto the a-Si film on the glasssubstrate 10 through the mask 40.

[0187] Here, a laser irradiated region a with the pulse laser passedthrough the dotted pattern 41 of the first mask region M₂₁ will be notedin the following description.

[0188]FIG. 19 shows the laser irradiated region a on the a-Si film withthe first shot of pulse laser beam passed through the dotted pattern 41.

[0189] In the laser irradiated region a, the beam width is 5 μm, and thepitch is equal at 5 μm. In the laser irradiated region a, the crystalgrows toward the middle portion from the outer peripheral side, and thewhole surface of the laser irradiated region a is poly-crystallized. Thelaser irradiated region a is poly-crystallized without undergoing anyheat influence from the adjacent laser irradiated region a.

[0190] Therefore, the laser irradiated region a is poly-crystallized inthe predetermined or larger crystal particle diameter.

[0191] Next, FIG. 20 shows a laser irradiated region bpoly-crystallized, when the a-Si film is irradiated with the second shotof pulse laser passed through the square ring pattern 42-1.

[0192] Since the glass substrate 10 continuously moves in the Xdirection, the laser irradiated region b at the second shot forms theouter periphery of the laser irradiated region a at the first shot. Thelaser irradiated region b is a square ring pattern having a beam widthof 5 μm. The laser irradiated region b is formed at the equal pitch of 5μm.

[0193] Therefore, in the laser irradiated region b, the crystal growstoward the middle portion from the outer peripheral side, and the wholesurface of the laser irradiated region b is poly-crystallized. The laserirradiated region b is poly-crystallized without undergoing any heatinfluence from the adjacent laser irradiated region b. Therefore, thelaser irradiated region b is poly-crystallized in the predetermined orlarger crystal particle diameter.

[0194] Next, FIG. 21 shows a laser irradiated region cpoly-crystallized, when the a-Si film is irradiated with the third shotof pulse laser passed through the square ring pattern 42-2.

[0195] Since the glass substrate 10 continuously moves in the Xdirection, the laser irradiated region c at the third shot forms theouter periphery of the laser irradiated region b at the second shot. Thelaser irradiated region c is a square ring pattern having a beam widthof 5 μm. The laser irradiated region c is formed at the equal pitch of 5μm.

[0196] Therefore, in the laser irradiated region c, the crystal growstoward the middle portion from the outer peripheral side, and the wholesurface of the laser irradiated region c is poly-crystallized. The laserirradiated region c is poly-crystallized without undergoing any heatinfluence from the adjacent laser irradiated region c. Therefore, thelaser irradiated region c is poly-crystallized in the predetermined orlarger crystal particle diameter.

[0197] As a result, the whole surfaces of the laser irradiated regionsa, b, c are poly-crystallized in the predetermined or larger crystalparticle diameter by the irradiation with three shots of pulse laser.

[0198] Also in the other laser irradiated regions, similarly asdescribed above, the a-Si film is repeatedly irradiated with the pulselaser as shown in FIGS. 19 to 21, and the a-Si film is continuouslypoly-crystallized.

[0199] The a-Si film on the glass substrate 10 is irradiated with thepulse laser passed through the mask 40 in this manner, and the glasssubstrate 10 continuously moves by the operation of the XYZ tilt stage21.

[0200] Thereby, when the a-Si film is irradiated with three shots ofpulse laser beams, for example, a Si film on the whole surface in thefirst mask region M₂₁ is poly-crystallized.

[0201] Therefore, for the a-Si film on the glass substrate 10, thenon-irradiated region with the pulse laser is successively filled up,and finally the whole surface of the a-Si film on the glass substrate 10is poly-crystallized.

[0202] As described above, according to the third embodiment, even whenthe mask 40 with the plurality of dotted patterns 41 and the pluralityof square ring patterns 42-1, 42-2 formed thereon is used, the effectcan be produced similarly as the first and second embodiments.

[0203] A fourth embodiment of the present invention will next bedescribed with reference to the drawings.

[0204] In the laser processing apparatus of the fourth embodiment, theconstitution of the mask 14 shown in FIG. 5 is changed. Therefore, thelaser processing apparatus will be described using the laser processingapparatus shown in FIG. 5.

[0205]FIG. 22 is a constitution diagram of a mask 50 for use in thelaser processing apparatus. In the mask 50, a plurality of polygonalpattern openings (hereinafter referred to as square patterns) 51-1 to51-3 are formed in longitudinal and lateral directions (XY directions).For the square pattern 51, the width and pitch are formed in such valuesthat the heat gradient appears in the laser irradiated region obtainedby irradiating the glass substrate 10 with the pulse laser.

[0206] The constitution of the mask 50 will concretely be described.

[0207] The mask 50 is divided, for example, into first to third maskregions M₃₁ to M₃₃. Respective origins Z₃₁ to Z₃₃ are set in the firstto third mask regions M₃₁ to M₃₃.

[0208] In the first mask region M₃₁, the plurality of square patterns51-1 are formed at the equal pitch in two rows in the Y direction. Thesquare pattern 51-1 is set at such a value that the heat gradient isgenerated in the laser irradiated region in the a-Si film, for example,such that the beam width of the laser irradiated region on the a-Si filmis about 5 μm or less.

[0209] In the second mask region M₃₂, the plurality of square patterns51-2 are formed at the equal pitch in two rows in the Y direction. Thesquare pattern 51-2 is smaller than the square pattern 51-1 by apredetermined size. The square pattern 51-2 is set at such a value thatthe heat gradient is generated in the laser irradiated region in thea-Si film, for example, such that the beam width of the laser irradiatedregion on the a-Si film is about 5 μm or less.

[0210] In the third mask region M₃₃, the plurality of square patterns51-3 are formed at the equal pitch in two rows in the Y direction. Thesquare pattern 51-3 is smaller than the square pattern 51-2 by apredetermined size.

[0211] The square pattern 51-3 is set at such a value that the heatgradient is generated in the laser irradiated region in the a-Si film,for example, such that the beam width of the laser irradiated region onthe a-Si film is about 5 μm or less.

[0212] The distance between the center of the square pattern 51-1 andthe origin Z₃₁, the distance between the center of the square pattern51-2 and the origin Z₃₂, and the distance between the center of thesquare pattern 51-3 and the origin Z₃₃ are the same.

[0213] Therefore, when the first to third mask regions M₃₁ to M₃₃ aresuperposed upon one another, the respective square patterns 51-1 to 51-3are superposed upon one another in a concentric position.

[0214] The operation of the apparatus constituted as described abovewill next be described.

[0215] The method of poly-crystallizing the a-Si film formed on theglass substrate 10 in the manufacturing process of the p-Si TFT liquidcrystal display is carried out as follows.

[0216] The excimer laser 11 intermittently outputs the pulse laser, forexample, at the repeated frequency of 200 to 500 Hz. The pulse laser isemitted to the mask 50 from the variable attenuator 12 through thelighting optical system 13.

[0217] The pulse laser is passed through the mask pattern formed on themask 50, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0218] Moreover, similarly as the first embodiment, the XYZ tilt stage21 continuously moves the glass substrate 10 at the conveyance speedsynchronized with the repeated frequency of the pulse laser beam.

[0219] The first, second, third, . . . shots of pulse laser beams outputfrom the excimer laser 11 are emitted onto the a-Si film on the glasssubstrate 10 through the mask 40.

[0220] Here, a laser irradiated region T with the pulse laser passedthrough the square pattern 51-1 of the first mask region M₃₁ will benoted in the following description.

[0221]FIG. 23 shows a laser irradiated region K₁ on the a-Si filmirradiated with the first shot of pulse laser beam passed through thesquare pattern 51-1.

[0222] In the laser irradiated region K₁, the beam width is 5 μm, andthe pitch is equal at 5 μm. In the laser irradiated region K₁, thecrystal grows toward the middle portion from the outer peripheral side,and the inside of the laser irradiated region K₁ is poly-crystallized inthe predetermined or larger crystal particle diameter. The laserirradiated region K₁ is poly-crystallized without undergoing any heatinfluence from the adjacent laser irradiated region K₁.

[0223] Additionally, since the heat gradient is small in a middleportion L of the laser irradiated region K₁, the portion ismicro-crystallized.

[0224] Next, FIG. 24 shows a laser irradiated region K₂ on the a-Si filmirradiated with the second shot of pulse laser passed through the squarepattern 51-2.

[0225] Since the glass substrate 10 continuously moves in the Xdirection, the laser irradiated region K₂ at the second shot forms theouter periphery of the laser irradiated region K₁ at the first shot. Thelaser irradiated region K₂ is a square pattern having a beam width of 5μm. The laser irradiated region K₂ is formed at the equal pitch of 5 μm.

[0226] Therefore, in the laser irradiated region K₂, the crystal growstoward the middle portion from the outer peripheral side, and the insideof the laser irradiated region K₂ is poly-crystallized in thepredetermined or larger crystal particle diameter. The laser irradiatedregion K₂ is poly-crystallized without undergoing any heat influencefrom the adjacent laser irradiated region K₁.

[0227] Additionally, since the heat gradient is small in the middleportion L of the laser irradiated region K₂, the portion ismicro-crystallized.

[0228] Next, FIG. 25 shows a laser irradiated region K₃ on the a-Si filmirradiated with the third shot of pulse laser passed through the squarepattern 51-3.

[0229] Since the glass substrate 10 continuously moves in the Xdirection, the laser irradiated region K₃ at the third shot forms theouter periphery of the laser irradiated region K₂ at the second shot.The laser irradiated region K₃ is a square pattern having a beam widthof 5 μm. The laser irradiated region K₃ is formed at the equal pitch of5 μm.

[0230] Therefore, in the laser irradiated region K₃, the crystal growstoward the middle portion from the outer peripheral side, and the wholesurface of the laser irradiated region K₃ is poly-crystallized. Thelaser irradiated region K₃ is poly-crystallized without undergoing anyheat influence from the adjacent laser irradiated region K₃. Therefore,the laser irradiated region K₃ is poly-crystallized in the predeterminedor larger crystal particle diameter.

[0231] As a result, the whole surfaces of the laser irradiated regionsK₁, K₂, K₃ are poly-crystallized in the predetermined or larger crystalparticle diameter by the irradiation with three shots of pulse laser.

[0232] Also in the other laser irradiated regions, similarly asdescribed above, the a-Si film is repeatedly irradiated with the pulselaser as shown in FIGS. 23 to 25, and the a-Si film is continuouslypoly-crystallized.

[0233] The a-Si film on the glass substrate 10 is irradiated with thepulse laser passed through the mask 50 in this manner, and the glasssubstrate 10 continuously moves by the operation of the XYZ tilt stage21.

[0234] Thereby, when the a-Si film is irradiated with three shots ofpulse laser beams, for example, the Si film on the whole surface in thefirst mask region M₃₁ is poly-crystallized.

[0235] Therefore, for the a-Si film on the glass substrate 10, thenon-irradiated region with the pulse laser is successively filled up,and finally the whole surface of the a-Si film on the glass substrate 10is poly-crystallized.

[0236] As described above, according to the fourth embodiment, even whenthe mask 50 with the plurality of square patterns 51-1 to 51-3 formedthereon is used, needless to say, the effect can be produced similarlyas the first to third embodiments.

[0237] A fifth embodiment of the present invention will next bedescribed with reference to the drawings.

[0238] In the laser processing apparatus of the fifth embodiment, theconstitution of the mask 14 shown in FIG. 5 is changed. Therefore, thelaser processing apparatus will be described using the laser processingapparatus shown in FIG. 5.

[0239]FIG. 26 is a constitution diagram of a mask 60 for use in thelaser processing apparatus. In the mask 60, a plurality of openings(hereinafter referred to as line patterns) 61 are formed in the Xdirection.

[0240] The line pattern 61 is formed in a direction corresponding to thegrowth direction of the crystal at a time of poly-crystallization of thea-Si film irradiated with the pulse laser on the glass substrate 10.

[0241] The constitution of the mask 60 will concretely be described.

[0242] The mask 60 is divided, for example, into first to fourth maskregions M₄₁ to M₄₄. The first to fourth mask regions M₄₁ to M₄₄ aredivided at an equal interval of the pitch Mp. Respective origins Z₄₁ toZ₄₄ are set in the first to fourth mask regions M₄₁ to M₄₄.

[0243] The line patterns 61 are formed in the positions which do notoverlap one another in the respective mask regions M₄₁ to M₄₄. The widthand pitch of the line pattern 61 are formed in such values that the heatgradient is generated in the laser irradiated region in the a-Si film onthe glass substrate 10. For example, the beam width of the laserirradiated region on the a-Si film is about 5 μm or less, and the pitchis 1 μm or more.

[0244] In the mask region M₄₁, the plurality of line patterns 61 areformed at the equal pitch in the Y direction. The position of one of theline patterns 61 is aligned with the origin Z₄₁.

[0245] In the mask region M₄₂, the plurality of line patterns 61 areformed at the equal pitch in the Y direction. The line pattern 61deviates from the line pattern 61 formed in the mask region M₄₁ by thewidth of one line pattern 61.

[0246] In the mask region M₄₃, the plurality of line patterns 61 areformed at the equal pitch in the Y direction. The line pattern 61deviates from the line pattern 61 formed in the mask region M₄₁ by thewidth of two line patterns 61.

[0247] In the mask region M₄₄, the plurality of line patterns 61 areformed at the equal pitch in the Y direction. The line pattern 61deviates from the line pattern 61 formed in the mask region M₄₁ by thewidth of three line patterns 61.

[0248] The operation of the apparatus constituted as described abovewill next be described.

[0249] The method of poly-crystallizing the a-Si film formed on theglass substrate 10 in the manufacturing process of the p-Si TFT liquidcrystal display is carried out as follows.

[0250] The excimer laser 11 intermittently outputs the pulse laser, forexample, at the repeated frequency of 200 to 500 Hz. The pulse laser isemitted to the mask 60 from the variable attenuator 12 through thelighting optical system 13.

[0251] The pulse laser is passed through the mask pattern formed on themask 60, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0252] Moreover, similarly as the first embodiment, the XYZ tilt stage21 continuously moves the glass substrate 10 at the conveyance speedsynchronized with the repeated frequency of the pulse laser beam.

[0253] The first, second, third, . . . shots of pulse laser output fromthe excimer laser 11 are emitted onto the a-Si film on the glasssubstrate 10 through the mask 60.

[0254] The a-Si film on the glass substrate 10 is irradiated with thepulse laser passed through the mask 60 in this manner, and the glasssubstrate 10 continuously moves by the operation of the XYZ tilt stage21.

[0255] Thereby, when the a-Si film is irradiated with four shots ofpulse laser, the Si film in each laser irradiated region ispoly-crystallized in the predetermined or larger crystal particlediameter by these shots.

[0256] Since the respective laser irradiated regions with these fourshots are adjacent to one another, the whole surfaces of the laserirradiated regions are continuously poly-crystallized.

[0257] Therefore, for the a-Si film on the glass substrate 10, thenon-irradiated region with the pulse laser is successively filled up,and finally the whole surface of the a-Si film on the glass substrate 10is poly-crystallized.

[0258] In this case, the polycrystal growth direction is vertical to themovement direction of the glass substrate 10 as shown in FIG. 27. Thatis, the laser irradiated region obtained by irradiating the a-Si filmwith the pulse laser beam passed through the line pattern 61 becomeslinear.

[0259] Since the heat gradient increases in a narrower width directionof the laser irradiated region, the crystal grows in the widthdirection. The width direction is vertical to the movement direction ofthe glass substrate 10.

[0260] Additionally, when the mask 14 shown in FIG. 5 is used, thecrystal grows in the narrower width direction of the laser irradiatedregion by the mask 14. The width direction is the movement direction (Xdirection) of the glass substrate 10.

[0261] As described above, according to the fifth embodiment, the mask60 with the plurality of line patterns 61 formed in the X directionthereon is used, and the glass substrate 10 is continuously moved in theX direction.

[0262] The whole surface of the a-Si film on the glass substrate 10 canbe poly-crystallized in the X direction (movement direction of the glasssubstrate 10). Therefore, when the mask 60 or the mask 14 shown in FIG.5 is used, the growth direction of the poly-crystallization on the glasssubstrate 10 can be controlled.

[0263] Additionally, also in the fifth embodiment, needless to say, theeffect can be produced similarly as the first to fourth embodiments.

[0264] A sixth embodiment of the present invention will next bedescribed with reference to the drawings.

[0265] In the laser processing apparatus of the sixth embodiment, theconstitution of the mask 14 shown in FIG. 5 is changed. Therefore, thelaser processing apparatus will be described using the laser processingapparatus shown in FIG. 5.

[0266]FIG. 28 is a constitution diagram of a mask 70 for use in thelaser processing apparatus. In the mask 70, a plurality of patternopenings (hereinafter referred to as line patterns) 71 are formed in anoblique direction with respect to the X and Y directions.

[0267] The line pattern 71 is formed in a direction corresponding to thegrowth direction of the crystal at a time of the poly-crystallization ofthe a-Si film irradiated with the pulse laser beam on the glasssubstrate 10, for example, in a direction of 45° with respect to the Xdirection.

[0268] The constitution of the mask 70 will concretely be described.

[0269] The mask 70 is divided, for example, into first to fourth maskregions M₅₁ to M₅₄. The first to fourth mask regions M₅₁ to M₅₄ aredivided at the equal interval of the pitch Mp. Respective origins Z₅₁ toZ₅₄ are set in the first to fourth mask regions M₅₁ to M₅₄.

[0270] The line patterns 71 are formed in the positions which do notoverlap one another in the respective mask regions M₅₁ to M₅₄. The widthand pitch of the line pattern 71 are formed in such values that the heatgradient is generated in the laser irradiated region in the a-Si film onthe glass substrate 10. For example, the beam width of the laserirradiated region on the a-Si film is about 5 μm or less, and the pitchis 1 μm or more.

[0271] In the mask region M₅₁, the plurality of line patterns 71 areformed at the equal pitch and inclined, for example, by 45° with respectto the X direction. The position of one of the line patterns 71 isaligned with the origin Z₅₁.

[0272] In the mask region M₅₂, the plurality of line patterns 71 areformed at the equal pitch and inclined, for example, by 45° with respectto the X direction. The line pattern 71 deviates in the Y direction fromthe line pattern 71 formed in the mask region M₅₁ by the width of oneline pattern 71.

[0273] In the mask region M₅₃, the plurality of line patterns 71 areformed at the equal pitch and inclined, for example, by 45° with respectto the X direction. The line pattern 71 deviates in the Y direction fromthe line pattern 71 formed in the mask region M₅₁ by the width of twoline patterns 71.

[0274] In the mask region M₅₄, the plurality of line patterns 71 areformed at the equal pitch and inclined, for example, by 45° with respectto the X direction. The line pattern 71 deviates from the line pattern71 formed in the mask region M₅₁ by the width of three line patterns 71.

[0275] The operation of the apparatus constituted as described abovewill next be described.

[0276] The method of poly-crystallizing the a-Si film formed on theglass substrate 10 in the manufacturing process of the p-Si TFT liquidcrystal display is carried out as follows.

[0277] The excimer laser 11 intermittently outputs the pulse laser, forexample, at the repeated frequency of 200 to 500 Hz. The pulse laser isemitted to the mask 70 from the variable attenuator 12 through thelighting optical system 13.

[0278] The pulse laser is passed through the mask pattern formed on themask 70, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0279] Moreover, similarly as the first embodiment, the XYZ tilt stage21 continuously moves the glass substrate 10 at the conveyance speedsynchronized with the repeated frequency of the pulse laser beam.

[0280] The first, second, third, . . . shots of pulse laser output fromthe excimer laser 11 are emitted onto the a-Si film on the glasssubstrate 10 through the mask 70.

[0281] The a-Si film on the glass substrate 10 is irradiated with thepulse laser passed through the mask 70 in this manner, and the glasssubstrate 10 continuously moves by the operation of the XYZ tilt stage21.

[0282] Thereby, when the a-Si film is irradiated with four shots ofpulse laser, the Si film in each laser irradiated region ispoly-crystallized in the predetermined or larger crystal particlediameter by these shots.

[0283] Since the respective laser irradiated regions with these fourshots are adjacent to one another, the whole surfaces of the laserirradiated regions are continuously poly-crystallized.

[0284] Therefore, for the a-Si film on the glass substrate 10, thenon-irradiated region with the pulse laser is successively filled up,and finally the whole surface of the a-Si film on the glass substrate 10is poly-crystallized.

[0285] As shown in FIG. 29, the polycrystal growth direction is verticalto the movement direction of the glass substrate 10. That is, the laserirradiated region obtained by irradiating the a-Si film with the pulselaser beam passed through the line pattern 71 becomes linear.

[0286] Since the heat gradient increases in the narrower width directionof the laser irradiated region, the crystal grows in the widthdirection. The width direction is vertical to the movement direction ofthe glass substrate 10.

[0287] As described above, according to the sixth embodiment, the mask70 is used in which the plurality of line patterns 71 are formed andinclined by 45° with respect to the X direction, and the glass substrate10 is continuously moved in the X direction.

[0288] Thereby, the whole surface of the a-Si film on the glasssubstrate 10 is inclined by 45° with respect to the X direction andpoly-crystallized. Therefore, also in the sixth embodiment, needless tosay, the effect can be produced similarly as the first to fifthembodiments.

[0289] A seventh embodiment of the present invention will next bedescribed with reference to the drawings.

[0290] In the laser processing apparatus of the seventh embodiment, theconstitution of the mask 14 shown in FIG. 5 is changed. Therefore, thelaser processing apparatus will be described using the laser processingapparatus shown in FIG. 5.

[0291]FIG. 30 is a constitution diagram of a mask 80 for use in thelaser processing apparatus.

[0292] In the mask 80, for example, four line patterns 81 are formed inthe same direction. The width and pitch of the line pattern 81 areformed in such sizes that the polycrystalline Si film having thepredetermined or larger crystal particle diameter is formed at the timeof the poly-crystallization of the a-Si film irradiated with the pulselaser.

[0293] The width of each line pattern 81 is formed in a slit widthlength to generate the heat gradient in the laser irradiated region,when the a-Si film is irradiated with the pulse laser. The pitch betweenthe line patterns 81 is formed in a pitch interval to generate the heatgradient in the laser irradiated region, when the a-Si film isirradiated with the pulse laser.

[0294] The constitution of the mask 80 will concretely be described.

[0295] The mask 80 is divided into a plurality of divided regions, forexample, first to fourth mask regions M₆₁ to M₆₄. Respective origins Z₆₁to Z₆₄ are disposed in the mask regions M₆₁ to M₆₄. Each interval amongthese mask regions M₆₁ to M₆₄ is formed in the interval having the equalpitch Mp.

[0296] The respective line patterns 81 are formed at the equal distancefrom the origins Z₆₁ to Z₆₄ in the mask regions M₆₁ to M₆₄. That is, theinterval of the line patterns 81 is formed at the equal pitch.

[0297] The number of line patterns 81 in each of the mask regions M₆₁ toM₆₄ is not limited to one. When the intervals of all the line patterns81 of the mask 80 have the equal pitch, a plurality of patterns may beformed in each of the mask regions M₆₁ to M₆₄.

[0298] Each line pattern 81 is formed so that the beam width of thelaser irradiated region on the a-Si film is, for example, about 5 μm orless, and the pitch is 1 μm or more. This is the condition for formingthe polycrystalline Si film having the predetermined or larger crystalparticle diameter.

[0299] The method of poly-crystallizing the a-Si film formed on theglass substrate 10 in the manufacturing process of the p-Si TFT liquidcrystal display is carried out as follows.

[0300] The excimer laser 11 intermittently outputs the pulse laser, forexample, at the constant repeated frequency of 200 to 500 Hz. The pulselaser beam is emitted to the mask 80 from the variable attenuator 12through the lighting optical system 13.

[0301] The pulse laser is passed through the mask pattern formed on themask 80, reaches the mirror 15, and is reflected by the mirror 15. Thepulse laser reflected by the mirror 15 is emitted onto the a-Si film onthe glass substrate 10 by the projection lens 16.

[0302] Moreover, the XYZ tilt stage 21 continuously moves the glasssubstrate 10 at the constant conveyance speed synchronized with therepeated frequency of the pulse laser beam. In this case, the conveyancedirection is the positive or negative X direction.

[0303] Subsequently, the XYZ tilt stage 21 moves the glass substrate 10in the Y direction by the distance corresponding to the width of thepulse laser beam.

[0304] Next, the XYZ tilt stage 21 again moves the glass substrate 10continuously in the X direction at the constant conveyance speed. Inthis case, the conveyance direction is the negative or positive Xdirection.

[0305] Thereafter, the XYZ tilt stage 21 repeats the movement at theconstant conveyance speed. The XYZ tilt stage 21 moves the glasssubstrate 10, for example, at the conveyance speed of about 200 to 500mm/s.

[0306] The a-Si film on the glass substrate 10 is irradiated with first,second, third, . . . shots of pulse laser beams output from the excimerlaser 11 through the mask 80.

[0307] The a-Si film on the glass substrate 10 is irradiated with thepulse laser beam passed through the mask 80 in this manner, and theglass substrate 10 moves at the constant conveyance speed by theoperation of the XYZ tilt stage 21.

[0308]FIG. 31 shows each laser irradiated region Fl poly-crystallizedwhen the a-Si film is irradiated with the first shot of pulse laserbeam. The pulse laser beam passed through each line pattern 81 of themask 80 is emitted onto the a-Si film on the glass substrate 10. Thea-Si film of the laser irradiated region F1 is poly-crystallized bythese pulse laser beams.

[0309] Each laser irradiated region F₁ is set such that each beam widthis 5 μm or less and the pitch Mp is 1 μm or more. Thereby, in each laserirradiated region F₁, the crystal grows toward the middle portion fromthe outer edge of the laser irradiated region F₁, and the whole surfaceof the laser irradiated region F₁ is poly-crystallized to form thepolycrystalline Si film having the predetermined or larger crystalparticle diameter.

[0310] Each laser irradiated region Fl does not undergo any heatinfluence from the adjacent laser irradiated region, and the a-Si filmis poly-crystallized.

[0311] Next, FIG. 32 shows a laser irradiated region F₂poly-crystallized when the a-Si film is irradiated with the second shotof pulse laser beam.

[0312] The second shot of pulse laser beam is emitted onto the a-Si filmat a timing at which the glass substrate 10 moves by the pitch intervalof each line pattern 81.

[0313] Therefore, for the laser irradiated regions F₂ of the secondshot, three laser irradiated regions F₂ are adjacent to the laserirradiated regions F₁ of the first shot. That is, the laser irradiatedregions F₁ and F₂ are formed by the pulse laser beams passed through thedifferent line patterns 81, not by the pulse laser beams passed throughthe same line pattern 81.

[0314] Therefore, even these laser irradiated regions F₂ do not undergoany heat influence from the adjacent laser irradiated region. The laserirradiated region F₂ is obtained by poly-crystallizing the a-Si film inthe predetermined or larger crystal particle diameter.

[0315] Next, FIG. 33 shows a laser irradiated region F₃poly-crystallized, when the a-Si film is irradiated with the third shotof pulse laser beam.

[0316] The third shot of pulse laser beam is emitted onto the a-Si filmat a timing at which the glass substrate 10 further moves by the pitchinterval of each line pattern 81.

[0317] Therefore, for the laser irradiated regions F₃ of the third shot,three laser irradiated regions F₃ are adjacent to the laser irradiatedregions F₂ of the second shot. Even these laser irradiated regions F₃ donot undergo any heat influence from the adjacent laser irradiatedregion. The laser irradiated region F₃ is obtained by poly-crystallizingthe a-Si film in the predetermined or larger crystal particle diameter.

[0318] Here, the respective laser irradiated regions F₁, F₂, F₃, . . .of the first, second, third, . . . shots of pulse laser beams havepartially overlapped portions g₁, g₂ as shown in FIG. 34. Even with theoverlapped portions g₁, g₂, the a-Si film is poly-crystallized in thepredetermined or larger crystal particle diameter.

[0319] Thereafter, similarly as described above, the a-Si film on theglass substrate 10 is irradiated with the pulse laser beam through themask 80, and the glass substrate 10 is moved at the constant conveyancespeed by the operation of the XYZ tilt stage 21.

[0320] Therefore, in the a-Si film on the glass substrate 10, the nonlaser irradiated region not irradiated with the pulse laser beam issuccessively filled up, and finally the whole surface of the a-Si filmon the glass substrate 10 is poly-crystallized.

[0321] As described above, in the seventh embodiment, the mask 80 withthe respective line patterns 81 formed at the equal pitch thereon isused, the glass substrate 10 is moved at the constant conveyance speed,and the pulse laser beam is emitted at the constant timing.

[0322] Thereby, for the a-Si film on the glass substrate 10, thenon-irradiated region with the pulse laser beam is successively filledup, and finally the whole surface of the a-Si film on the glasssubstrate 10 is poly-crystallized in the predetermined or larger crystalparticle diameter.

[0323] An eighth embodiment of the present invention will next bedescribed with reference to the drawings.

[0324] In the eighth embodiment, a method of manufacturing the p-Si TFTliquid crystal display using any one of the laser processing apparatusesof the first to seventh embodiments will be described.

[0325]FIG. 35 is a constitution diagram showing one example of the TFTliquid crystal display in a manufacturing process. A TFT liquid crystaldisplay 90 includes: a plurality of pixel sections 91; a driver 92 ofeach pixel section 91 formed around the pixel section 91; and aperipheral circuit 93 including a gate array, D/A converter, and thelike.

[0326] When the TFT liquid crystal display 90 is manufactured, the a-Sifilm is formed on the glass substrate of the TFT liquid crystal display90. On the a-Si film, the polycrystalline Si film is formed in a regioncorresponding to the plurality of pixel sections 91, driver 92, andperipheral circuit 93.

[0327] For example, a memory and CPU are expected to be directly mountedparticularly in the region corresponding to the driver 92 and peripheralcircuit 93. In the region, a property of a film quality is demanded tobe enhanced.

[0328] To form the polycrystalline Si film in the region correspondingto the plurality of pixel sections 91, the laser processing apparatusaccording to any one of the first to seventh embodiments, for example,the first embodiment is applied.

[0329] The pulse laser beam repeatedly output from the excimer laser 11is passed through each line pattern 20 of the mask 14 shown in FIG. 2,and emitted onto the a-Si film corresponding to the pixel section 91 bythe projection lens 16.

[0330] On the other hand, the XYZ tilt stage 21 continuously moves theglass substrate 10, for example, in the X direction at the conveyancespeed synchronized with the repeated frequency of the pulse laser beam,next moves the substrate in the Y direction by a distance correspondingto a length of the line beam, and subsequently moves the substratecontinuously in the X direction again.

[0331] Thereby, the non laser irradiated region of the a-Si film formingthe pixel section 91 is successively filled up. Finally, the wholesurface of the a-Si film on the pixel section 91 is poly-crystallized.

[0332] To form the polycrystalline Si film in the region correspondingto the plurality of drivers 92 and peripheral circuits 93, the laserprocessing apparatus according to any one of the first to seventhembodiments, for example, the first embodiment is applied.

[0333] The pulse laser beam passed through the mask 14 is emitted ontothe a-Si film corresponding to the driver 92 and peripheral circuit 93by the projection lens 16. The laser irradiated region is shown as afield 94 of the projection lens 16.

[0334] On the other hand, the XYZ tilt stage 21 moves the glasssubstrate 10 at the conveyance speed synchronized with the repeatedfrequency of the pulse laser beam. The glass substrate 10 continuouslymoves in a direction extending along a longitudinal direction of thedriver 92 and peripheral circuit 93, for example, in the Y direction (orthe X direction).

[0335] Finally the whole surface of the a-Si film on the driver 92 andperipheral circuit 93 is poly-crystallized by scanning the pulse laserbeam.

[0336]FIG. 36 is a constitution diagram showing one example of anotherTFT liquid crystal display in the manufacturing process.

[0337] A TFT liquid crystal display 100 includes: a plurality of pixelsections 101; a plurality of drivers 102 formed around the respectivepixel sections 101;

[0338] and a plurality of peripheral circuits 103 including the gatearray, D/A converter, and the like.

[0339] A size of the driver 102 or the peripheral circuit 103 is formedto be smaller than a size of the field 94 of the projection lens 16.

[0340] To form the polycrystalline Si film in the region correspondingto the pixel sections 101 of the TFT liquid crystal display 100, thelaser processing apparatus according to any one of the first to seventhembodiments, for example, the first embodiment is applied.

[0341] The pulse laser beam repeatedly output from the excimer laser 11is passed through each line pattern 20 of the mask 14 shown in FIG. 6,and emitted onto the a-Si film corresponding to the pixel section 101 bythe projection lens 16.

[0342] On the other hand, the XYZ tilt stage 21 continuously moves theglass substrate 10, for example, in the X direction at the conveyancespeed synchronized with the repeated frequency of the pulse laser beam,next moves the substrate in the Y direction by the distancecorresponding to the length of the line beam, and subsequently moves thesubstrate continuously in the X direction again.

[0343] Thereby, the non laser irradiated region of the a-Si film formingthe pixel section 101 is successively filled up. Finally, the wholesurface of the a-Si film on the pixel section 101 is poly-crystallized.

[0344] To form the polycrystalline Si film in the region correspondingto the plurality of drivers 102 and peripheral circuits 103, the laserprocessing apparatus according to any one of the first to seventhembodiments, for example, the first embodiment is applied.

[0345] The pulse laser beam passed through the mask 14 is emitted ontothe a-Si film corresponding to the driver 102 and peripheral circuit 103by the projection lens 16.

[0346] On the other hand, the XYZ tilt stage 21 moves the glasssubstrate 10 at the conveyance speed synchronized with the repeatedfrequency of the pulse laser beam. The glass substrate 10 continuouslymoves in a direction extending along a longitudinal direction of thedriver 102 and peripheral circuit 103, for example, in the Y direction(or the X direction).

[0347] Finally the whole surface of the a-Si film on the driver 102 andperipheral circuit 103 is poly-crystallized by scanning the pulse laserbeam.

[0348] As described above, according to the eighth embodiment, theregions corresponding to the plurality of pixel sections 91, 101,drivers 92, 102, and peripheral circuits 93, 103 in the TFT liquidcrystal displays can be poly-crystallized.

[0349] Particularly the properties of the film qualities of the regionscorresponding to the drivers 92, 102 and peripheral circuits 93, 103, onwhich the memory and CPU are expected to be directly mounted, can beenhanced.

[0350] In the TFT liquid crystal display 100 shown in FIG. 36, the sizeof the driver 102 or the peripheral circuit 103 is formed to be smallerthan the size of the field 93 of the projection lens 16. Therefore, theoverlap in the irradiation with the pulse laser beam can be reduced. Acapability of the polycrystalline Si film can be enhanced.

[0351] In the eighth embodiment, all the regions corresponding to theplurality of pixel sections 91, 101, drivers 92, 102, and peripheralcircuits 93, 103 are poly-crystallized. This is not limited. Forexample, only regions for forming semiconductor devices such as CPU andmemory may be poly-crystallized in the regions of the drivers 92, 102and peripheral circuits 93, 103.

[0352] A ninth embodiment of the present invention will next bedescribed with reference to the drawings.

[0353]FIG. 37 is a schematic constitution diagram of an exposure devicesuch as a stepper. A laser deice 110 outputs a laser beam for subjectinga work 111 to an exposure processing. The work 111 is, for example, theglass substrate of the liquid crystal display.

[0354] A lighting optical system 112 and mirror 113 are disposed on anoptical path of the laser beam. A mask 114 and image forming lens system115 are disposed on a reflected light path of the mirror 113. Thelighting optical system 112 shapes the laser beam output from the laserdevice 110 and uniforms a light strength.

[0355] A plurality of pattern openings are formed in the mask 114. Thewidth and pitch of the pattern opening is set to a value, for example,in accordance with the exposure processing of the glass substrate 111 ofthe liquid crystal display. For example, the mask 14 shown in FIG. 6,mask 30 shown in FIG. 12, mask 40 shown in FIG. 18, mask 50 shown inFIG. 22, mask 60 shown in FIG. 26, mask 70 shown in FIG. 28, and mask 80shown in FIG. 30 can be applied to the mask 114.

[0356] An XYZ stage 116 has the glass substrate 111 mounted thereon, andmoves the glass substrate 111 in the XY directions and Z direction. TheXYZ stage 116 moves the glass substrate 111 by each predetermineddistance in one direction.

[0357] When the XYZ stage 116 moves the glass substrate 111 by eachpredetermined distance, the respective laser irradiated regions on theglass substrate 111 irradiated with the laser beams passed through thepattern openings of the mask 114 do not overlap one another.

[0358] The operation of the apparatus constituted as described abovewill next be described.

[0359] As the mask 114, for example, the mask 14 shown in FIG. 6 isapplied.

[0360] For example, in the manufacturing process of the p-Si TFT liquidcrystal display, the thin a-Si film is formed on the glass substrate111, and the thin film is coated with a resist and subjected to theexposure processing. Thereafter, the manufacturing process includesimage developing, etching processing, and removing of the resist.

[0361] The exposure device of the ninth embodiment is used in theexposure processing during the manufacturing process.

[0362] The first shot of laser beam output from the laser device 110 isshaped and uniformed by the lighting optical system 112. The laser beamis reflected by the mirror 113, and emitted onto the mask 114.

[0363] The laser beam is passed through the line pattern 20 of the mask114, and emitted onto the glass substrate 111 of the liquid crystaldisplay by a projection lens system.

[0364]FIG. 38 shows a linear exposed region and exposure strength by thefirst shot of laser beam. The surface of the glass substrate 111 iscoated with a resist film. The resist film is subjected to the exposureprocessing in the exposed region having an exposure strength higher thana resist exposure threshold value.

[0365] Subsequently, the XYZ stage 116 moves the glass substrate 111 bya distance corresponding to the half of the pitch of the line pattern ofthe mask 114. The movement direction of the glass substrate 111 isvertical to the longitudinal direction of the line pattern 20 of themask 114.

[0366] Next, the laser device 110 outputs the second shot of laser beam.The laser beam is shaped and uniformed by the lighting optical system112, and reflected by the mirror 113. The laser beam is passed throughthe line pattern 20 of the mask 114 and emitted onto the glass substrate111 by the projection lens system.

[0367]FIG. 39 shows the linear exposed region and exposure strength bythe second shot of laser beam. The glass substrate 111 is subjected tothe exposure processing in the exposed region having the exposurestrength higher than the resist exposure threshold value. The exposedregion of the second shot is formed in each interval between the exposedregions of the first shot.

[0368] As a result, a linear pattern is transferred to the resist on theglass substrate 111 by the second exposure processing as shown in FIG.36.

[0369] Additionally, when the plurality of line patterns formed on themask 114 are used to perform the resist exposure processing, and eachinterval between the line patterns is narrowed, the line pattern cannotbe resolved by the vicinity of a resolution limit by the projection lenssystem.

[0370] Therefore, as shown in FIG. 41, the exposure strengthcontinuously becomes higher than the resist exposure threshold value.Thereby, the exposed region of the line pattern does not appear.Therefore, the resist on the glass substrate 111 is exposed by a broadpattern.

[0371] Even in this case, according to the eighth embodiment of thepresent invention, even when the exposed region of the line pattern isnarrowed, each exposed region can be resolved and the exposureprocessing can be performed. The linear pattern, which has notheretofore been achieved, can be transferred onto the glass substrate111 with precision and at high resolution.

[0372] For example, the respective laser irradiated regions do notcompletely overlap one another, and the mask is formed so that a part ofthe laser irradiated region has the overlapped portion. This mask may beused to perform the laser processing and exposure. Even in this case,the effect of the present invention can be obtained.

[0373] The openings formed in the masks 13, 30, 40, 50, 60, 70, 80 and114 explained in the first to ninth embodiments may be any holesthorough which the light such as a pulse laser can passes. For example,a phase shift mask may be used as the mask having these openings.

What is claimed is:
 1. A laser processing method for irradiating a maskwith a plurality of openings formed therein with a pulse laser, andirradiating a plurality of portions of a work to be processed with saidpulse laser transmitted through said plurality of openings at the sametime, said method comprising: moving said mask and said work withrespect to each other and emitting said pulse laser a plurality oftimes; and setting a relation between a relative movement speed of saidmask and said work and an emission timing of said pulse laser such thatrespective laser irradiated regions disposed adjacent to one another onsaid work are formed by irradiation with said pulse laser transmittedthrough said openings formed in positions different from one another onsaid mask, and boundaries of said laser irradiated regions disposedadjacent to each other contact at least each other.
 2. The laserprocessing method according to claim 1, further comprising: emittingsaid pulse laser at a constant timing a plurality of times; and movingsaid work at a constant speed.
 3. The laser processing method accordingto claim 1, further comprising: moving said mask and said work withrespect to each other so that said boundaries of said laser irradiatedregions disposed adjacent to each other overlap each other.
 4. The laserprocessing method according to claim 1, further comprising: allowingsaid mask to have a width of said opening and a pitch between saidopenings formed in a width length and a pitch interval determined byphysical properties of said work, when said work is irradiated with saidpulse laser; moving said mask and said work with respect to each otherand emitting said pulse laser a plurality of times; andpoly-crystallizing said work of the laser irradiated region irradiatedwith said pulse laser in said work.
 5. The laser processing methodaccording to claim 1, wherein said work is a silicon film formed on asubstrate, said mask has a width of said opening and a pitch betweensaid openings formed in a width length and a pitch interval such that aheat gradient is generated in said laser irradiated region on saidsilicon film, and said silicon film is irradiated with said pulse laser,and said silicon film of said laser irradiated region ispoly-crystallized to form a polycrystalline silicon film having apredetermined or larger particle diameter.
 6. The laser processingmethod according to claim 1, wherein said mask has the plurality ofopenings formed in the same shape, and an interval between saidplurality of openings is formed at an equal pitch.
 7. The laserprocessing method according to claim 1, wherein said mask has saidopening formed in any one shape of a linear shape, a polygonal shape, aring shape, a dotted shape, a plurality of polygonal shapes havingdifferent sizes, and a linear shape inclined with respect to a movementdirection of said mask.
 8. The laser processing method according toclaim 1, wherein said mask is divided into a plurality of regions, and ashape of said opening is formed in a portion in which the dividedregions superposed upon one another do not overlap one another.
 9. Thelaser processing method according to claim 1, wherein said work is asilicon film formed on a substrate, and said mask has said plurality ofopenings formed in a direction corresponding to a growth direction of acrystal, when said silicon film is irradiated with said pulse laser andpoly-crystallized.
 10. A laser processing method for irradiating a maskwith a plurality of linear openings formed therein with a pulse laser,and irradiating a plurality of portions of a silicon film with saidpulse laser transmitted through said plurality of openings at the sametime, said method comprising: allowing said mask to have said pluralityof openings formed in the same direction, and have a width of saidopening and a pitch between said openings formed in a width length and apitch interval such that a heat gradient is generated in a laserirradiated region at a time of irradiation of said silicon film withsaid pulse laser; moving said silicon film in one direction at aconstant speed and emitting said pulse laser at a constant timing aplurality of times; setting the emission timing of said pulse laser suchthat said laser irradiated regions disposed adjacent to one another onsaid silicon film are formed by irradiation with said pulse lasertransmitted through said openings formed in positions different from oneanother on said mask, and boundaries of said laser irradiated regionsdisposed adjacent to each other contact at least each other; andpoly-crystallizing said silicon film of said laser irradiated region toform a polycrystalline silicon film having a predetermined or largerparticle diameter, and continuously forming a plurality of saidpoly-crystallized laser irradiated regions.
 11. A laser processingapparatus for irradiating a mask with a plurality of openings formedtherein with a pulse laser, and irradiating a plurality of portions of awork to be processed with said pulse laser transmitted through saidplurality of openings at the same time, said apparatus comprising: alaser device which outputs said pulse laser; a moving section whichmoves said mask and said work with respect to each another; and acontroller which controls said moving section to move said mask and saidwork with respect to each other, and controls said laser device to emitsaid pulse laser a plurality of times, wherein said controller controlssaid moving section to move said mask and said work with respect to eachother so that respective laser irradiated regions disposed adjacent toone another are irradiated with said pulse laser transmitted throughsaid openings different from one another among said plurality ofopenings, and boundaries of said laser irradiated regions disposedadjacent to each other contact at least each other.
 12. The laserprocessing apparatus according to claim 11, wherein said controllercontrols said laser device to emit said pulse laser at a constant timinga plurality of times, and controls said moving section to move said workat a constant speed.
 13. The laser processing apparatus according toclaim 11, wherein said controller controls said moving section and saidlaser device to move said mask and said work with respect to each otherso that said boundaries of said laser irradiated regions disposedadjacent to each other overlap each other.
 14. The laser processingapparatus according to claim 11, wherein said mask has a width of saidopening and a pitch between said openings in a width length and a pitchinterval determined by physical properties of said work, when said workis irradiated with said pulse laser, said mask and said work are movedwith respect to each other and said pulse laser is emitted a pluralityof times, and said work of the laser irradiated region irradiated withsaid pulse laser in said work is poly-crystallized.
 15. The laserprocessing apparatus according to claim 11, wherein said work is asilicon film formed on a substrate, a width of said opening and a pitchbetween said openings are formed in a width length and a pitch intervalsuch that a heat gradient is generated in said laser irradiated regionon said silicon film, and said controller controls said moving sectionand said laser device to irradiate said silicon film with said pulselaser, and said silicon film is poly-crystallized to form apolycrystalline silicon film having a predetermined or larger particlediameter.
 16. The laser processing apparatus according to claim 11,wherein said opening is formed in any one shape of a linear shape, apolygonal shape, a ring shape, a dotted shape, a plurality of polygonalshapes having different sizes, and a linear shape inclined with respectto a movement direction of said mask.
 17. The laser processing apparatusaccording to claim 11, wherein said mask is divided into a plurality ofregions, and said plurality of openings are formed in portions in whichthe divided regions superposed upon each other do not overlap eachother.
 18. The laser processing apparatus according to claim 11, whereina width length of said opening is 5 μm or less, and a pitch between saidplurality of openings is formed in 1 μm or more.
 19. The laserprocessing apparatus according to claim 11, further comprising alighting optical system which shapes and uniforms said pulse laseroutput from said laser device and irradiates said work through saidmask.
 20. A laser processing apparatus for irradiating a silicon filmwith a pulse laser, comprising: a laser device which outputs said pulselaser; a mask having a plurality of linear openings formed in the samedirection, and having a width of the opening and a pitch between saidopenings formed in a width length and a pitch interval such that a heatgradient is generated in a laser irradiated region at a time ofirradiation of said silicon film with said pulse laser; a moving sectionwhich moves said mask and said silicon film with respect to each other;and a controller which controls said moving section to move said maskand said silicon film with respect to each other, and controls saidlaser device to emit said pulse laser a plurality of times, wherein saidcontroller allows said respective laser irradiated regions disposedadjacent to one another on said silicon film to be formed by irradiationwith said pulse laser transmitted through said openings formed inpositions different from one another on said mask, and allows said laserdevice to output said pulse laser at a timing at which boundaries ofsaid laser irradiated regions disposed adjacent to each other contact atleast each other, and said silicon film of said laser irradiated regionis poly-crystallized to form a polycrystalline silicon film having apredetermined or larger particle diameter, and a plurality of saidpoly-crystallized laser irradiated regions are continuously formed.